I seek renewed funding to continue the project of my original proposal. I do basic research into the biological meaning of leaf variability; and I develop methods for the analysis of biological images. The aim of my project is twofold. First, to automate using a video digitizer, the Fourier Transform-base Boundary Method I invented (Kincaid & Schneider 1983). Automation is necessary to get an order of magnitude increase in leaf images processed (100 vs 10 per hr) so that we can adequately sample and understand the fantastic leaf variability present in populations of plants. Rapid, precise, and accurate image acquisition, noise rejection, rotation blowup, edge detection, assignment of x,y coordinates, and Fourier analysis, all aimed at a schedule of 100 leaves per hour, are not trivial tasks. The second aim of the project is to continue doing morphometric, heat transfer, and gas exchange research with high degrees of freedom for leaves of Sassafras from trees in natural populations. The objectives here are to determine if predictable patterns in form exist in space in time. Then, do the different forms confer different functions? The functions I will measure are convective heat exchange ability and gas exchange responses (water relations & carbon dioxide fixation). Considering that leaves house the photosynthetic machinery that produces the trophic energy for all terrestrial biota; and considering that leaves provide the very foundation of the human economy, it is interesting that the meaning behind variability in leaf form eludes explanation. We selected the small tree, Sassafras, as a model plant because it is locally abundant and because we can partition the leaves into discrete categories of form (entire margins; and lobed margin forms) making it easier to handle than a species having leaf variability displayed along a continuum. Circumscribing form for a sample of biological images is a morphometric task the mastery of which is superb training for any science student. Because form and function are always linked, each biological discipline performs at least some type of computer- assisted morphometric research. Since the concepts of shape quantification, boundary landmarks, image complexity, symmetry, image reconstruction & modification, pattern recognition, and statistical testing for shape heterogeneity are similar whether one deals with cancer cells or leaves, students participating in this project will experience some of the theory and the exciting discoveries we make in the study of biological form. Participating students work with me on topics of broad biological interest; such as, can one predict the shape of derivative structures given the form of precursors? Obviously, computer skills in the statistical and graphical analysis of data are easily transferred to any science. Finally, our experiments on convective cooling, are educating for the student, because techniques for understanding heart transfer in leaves do not differ from those used on any biological subject. Finally, we are analyzing data and working on manuscripts for submission to journals and the contributions of my MBRS student Mr. Ramirez, will earn him joint authorship. The best career building strategy I can conceive is for an undergraduate biology major to be in such a position; and the help of MBRS has made this strategy possible.